Have you ever noticed your period blood isn't always the same colour? Sometimes it's bright red, other times it's brown or even black. This colour variation might seem strange, but it's totally normal. We explore why your period blood may be brown and what it means for your menstrual health.


Why is Your Period Blood, Brown?

Sometimes, period blood looks brown instead of red. This happens because the blood stays in the uterus longer and reacts with oxygen, resulting in a brown colour. It's normal, especially at the start or end of your period when the flow is light. But if it happens a lot or comes with other problems, like bad pain or strange smells, it's best to talk to a doctor.


What Does Period Blood Colour Mean?

The colour of your period blood can vary based on several factors, including blood flow, how long it's been in your uterus, and exposure to oxygen. While it's common for period blood to range from bright red to dark brown, the colour variations can sometimes be puzzling. However, understanding these colours can provide valuable insights into your menstrual health.

Bright Red

Fresh menstrual blood is typically bright red. This indicates that the blood is flowing quickly from the uterus and hasn't had much time to oxidize. Bright red blood is considered normal and healthy, especially during the initial days of your period when the flow is typically heavier.

Brown or Dark Red

As menstrual blood remains in the uterus for a longer period, it may appear brown or dark red. This colour change occurs as the blood ages and oxidizes. It's common to see brown or dark red blood at the beginning or end of your period when the flow is lighter. While it may look different from bright red blood, brown or dark red blood is usually a matter not to worry about.


Sometimes, period blood may appear black, especially towards the end of your period when the flow is minimal. This dark colouration occurs when the blood has been in the uterus for an extended period, causing further oxidation. While black blood may look alarming, it's typically not a cause for concern and is considered a normal variation.

Pink or Light Red

Occasionally, you may notice period blood that appears pink or light red, especially during lighter flow days. This colour variation can result from a mix of fresh blood and cervical mucus. It's generally nothing to worry about and may indicate the tail end of your period.

Grey or Green

In rare cases, period blood may have a grey or greenish hue. This can be a sign of infection or a more serious underlying health condition, such as a sexually transmitted infection or pelvic inflammatory disease. If you notice unusual colours like grey or green, it's essential to consult a healthcare provider for evaluation and treatment.

Understanding the colour variations in your period blood can help you monitor your menstrual health and detect any potential issues early on. If you have concerns about the colour or consistency of your period blood, don't hesitate to seek guidance from a healthcare professional.


Reasons for Brown Period Blood

Brown period blood might worry you when it shows up during your period. But it's quite normal and happens for different reasons. Knowing why it happens can ease your mind and help you understand what's going on. Here are some simple reasons for brown period blood:

Blood oxidation

When blood comes in touch with air, it goes through a process known as oxidation, which causes it to brown. This is a natural process that occurs when blood leaves the body at a slower rate, providing more time for oxidation to occur. 

Slow flow

Menstrual blood may take longer to leave the uterus, resulting in a darker shade. This can occur when the flow is lighter or when there are clots, which can obstruct the blood's outflow and result in darker shades.

Hormonal changes

Fluctuations in hormone levels, particularly estrogen and progesterone, can affect the colour of your period blood. These hormonal changes can sometimes lead to brownish-coloured blood during menstruation.



In conclusion, the colour of your period blood can vary based on different factors like speed of flow and exposure to oxygen. Bright red is normal, while darker shades are common too. Understanding these variations can help you monitor your menstrual health. If you notice unusual colours with other symptoms, consult a healthcare provider. Stay informed and take charge of your menstrual health for peace of mind.